Typical prior art reciprocating saw blades include a blade portion having a cutting edge defined by a plurality of teeth axially spaced relative to each other along one side of the blade, and a non-working edge formed on an opposite side of the blade relative to the cutting edge. The inner ends of such reciprocating saw blades define tangs for releasably connecting the blades to chucks of reciprocating saws. The outer ends of reciprocating saw blades do not define tangs and are not connectable to chucks of reciprocating saws. Rather, the outer ends of reciprocating saw blades are free ends and the cutting edges of such saw blades extend to the distal tips of the free ends.
A reciprocating saw machine is a hand-held power saw including a chuck that releasably engages only one end of the reciprocating saw blade (i.e., the tang on the inner end of the saw blade) and drives the inner end and thus the saw blade in a reciprocating motion through a work piece. Reciprocating saw machines are typically driven by electric motors (e.g., cord or cordless saws), or are pneumatically driven. The reciprocating motion can be an orbital cutting action, a straight or linear cutting action, or an angled cutting action. Reciprocating saws are sometimes referred to as recip saws, or jig saws, and reciprocating saw blades are sometimes referred to as recip blades or jig saw blades. A jig saw includes a handle and a relatively small, thin blade oriented to be used comfortably on horizontal surfaces. A recip saw usually has a larger blade and blade-mounting assembly resembling that of a jig saw, but includes a handle oriented to allow the saw to be used comfortably on vertical surfaces. Well known reciprocating saws are sold under the brand names “Sawzall™” by Milwaukee Electric Tool Corporation and “Tiger Saw™” by Porter-Cable Corporation. A reciprocating saw blade is a saw blade adapted for use in a reciprocating saw, such as a recip saw or a jig saw, where the inner end of the blade engages the chuck of a reciprocating saw, and the outer end is a free end of the blade that does not engage the chuck during use.
Standardized or universal chucks and corresponding tangs allow reciprocating saw users to easily change reciprocating saw blades due to blade wear or to customize the saw blade to suit a particular application. For instance, blades with finer teeth may be used for cutting through metal, while abrasive blades may be used for cutting through tile. Similarly, long, general-purpose blades may be used for cutting through a variety of materials, from drywall to tree-limbs, lumber or even nails.
The most common and safe way to use a reciprocating saw, such as a jig saw or recip saw, is to place the foot or shoe of the saw against the workpiece to help keep the saw steady and reduce vibration, i.e., to ensure the push and pull forces move the blade through the workpiece as opposed to moving the body of the saw or the workpiece itself. Because most workpieces are relatively small as compared to typical reciprocating saw blades, and because the length of each saw blade stroke is relatively short (typically about ¾ inch to about 1¼ inches), reciprocating saw blades typically incur most wear and/or wear out along a primary cutting surface defined by the inner end of the cutting edge adjacent to the foot or shoe. As a result, it is frequently necessary to discard a reciprocating saw blade that is worn out only along the inner portion of the blade, whereas the outer portion of the blade may not be worn out at all and/or may have significant wear life remaining. This problem can be particularly acute in connection with relatively expensive blades, and/or blades made with relatively expensive cutting edge materials, such as reciprocating saw blades with carbide and/or diamond grit cutting edges.
In previous attempts to solve this problem, blade manufacturers have made shorter reciprocating saw blades so that users consume the entire cutting edge and reduce waste and cost. However, short blades have limited capabilities as they are not well suited to handle large workpieces. As a result, reciprocating saw users may be required to obtain multiple blades of differing lengths to suit particular workpiece restraints, thereby increasing costs and requiring more frequent blade changes.
It is an object of the present invention to overcome one or more of the above-described drawbacks and/or disadvantages of the prior art.